In 2012 European Telecommunications Standards Institute (ETSI) published white paper on Network Function Virtualization.

The main idea of Network Function Virtualization is separation of Network Function from hardware it runs on by using virtualization.

Network Function is functional block within a network infrastructure that has well-defined external interfaces and well-defined functional behavior, practically it is in example network node or physical appliance.

NFV Framework is composed of three components:

• Virtualized Network Functions (VNF) – software implementation of Network Function which runs on NFVI
• Network Function Virtualization Infrastructure (NFVI) – hardware and software resources that allows VNFs to work.
• Network Function Virtualization Management and Orchestration (NFV-MANO) -orchestration and management of physical and software resources that supports the infrastructure virtualization and manage the lifecycle of VNFs

ETSI NFV High Level Architecture

VNF can be applied to any data plane packet processing and control plane function in either mobile or fixed networks. According to ETSI, there are potential example of VNF usage:

• Switching elements, like routers
• Mobile networks nodes, like RNC, eNode B
• Tunneling gateway element, like IPSec/SSL VPN gateways
• Traffic analysis, like DPI, QoE measurements
• NGN signaling, like SBCs, IMS
• Security functions, like firewalls, spam protection.

 This approach results in many benefits:

• Consolidation of the network
• Automated management of virtualized resources
• Elasticity and unlimited scalability of network
• Reduced equipment costs